The present invention relates to a frame preferably usable for in-line skates or ice skates.
Said conventional frames are suitable to connect an overlying shoe to a plurality of in-line wheels, which can roll on the ground, or with an ice-skating blade.
Frames are currently in use which have a transverse cross-section, shaped like an inverted letter U, forming an upper base and two lateral wings, or walls, that protrude downward.
Said type of frame, preferably obtained by extrusion and then shaped by multiple milling operations, is associated with the shoe through two or more interconnection means, such as for example two screws that pass through holes provided in the base.
In turn, three or more in-line wheels are associated with the frame by means of respective hubs arranged transversely to said two wings.
U.S. Pat. No. RE-35,993 discloses a supporting device which is associated, in an upper region, with the sole of a shoe for skates and comprises a frame for connection to an ice-skating blade or to at least three rotatable wheels.
Such frame can be obtained from an extruded profiled element that is shaped approximately like an inverted letter U and has three transverse planes, namely an upper one, an intermediate one, and a lower one, arranged approximately horizontally, so as to interconnect two lateral vertical walls below which two facing wings protrude.
Said extruded profiled element can be conveniently machined by removing material so as to obtain a first plate and a second plate that protrude upward in order to engage said shoe.
Said first and second plate, formed respectively at the heel region and the tip region of the foot, have perforated upper walls, so as to allow the passage of means, such as screws, for connection to the sole of the shoe.
The upper surface of the first plate is obtained by machining the upper plane. Otherwise the upper surface of the second plate is preferably obtained by machining the intermediate plane, so that the points of contact between the frame and the shoe arrange themselves on staggered planes.
In said wings, which protrude downward, it is possible to provide slots and holes for the possibly adjustable connection of said wheels.
The main drawback of said conventional skates is that they do not have an adequate rigidity with respect to torsions and lateral forces that can be generated during sports practice.
Accordingly, an excessive stress is applied by said forces to the regions of the frame that lie proximate to the hubs, as well as to the hubs themselves, which, by acting as a connection between the two wings, are necessarily stressed by the weight of the user, by said lateral and torsional forces, and by external forces caused, for example, by accidental impacts or falls.
The aim of the present invention is therefore to solve the above noted problems, eliminating the drawbacks of the cited prior art, by providing a frame that allows to achieve an optimum distribution of stresses caused not only by vertical forces, such as the weight of the user, but also by the lateral forces that can occur during sports practice.
Within this aim, an important object is to provide a frame that allows to obtain said optimum stress distribution while maintaining a shape that has an advantageous aesthetic impact.
Another object is to provide a frame that maintains a high mechanical strength while being very light.
Another object is to provide a frame that is structurally simple and has low manufacturing costs.
This aim and these and other objects that will become better apparent hereinafter are achieved by a frame, particularly for in-line skates, comprising two mutually facing approximately vertical walls, transversely to which there are, along the same longitudinal axis, multiple holes for placing the hubs of respective wheels, characterized in that it has, in a transverse cross-section, an oval shape which is closed in the interspace between at least two adjacent wheels.